Double twist spindle

ABSTRACT

The present invention related to a double twist spindle for the twisting and assembling of textile filaments. The spindle assembly comprises a stator, a rotor, several layers of feed bobbins mounted on the stator, with each layer of bobbins regularly distributed around the spindle axis, with the vertical planes defined by the axis of a plurality of bobbins of two successive layers arranged in the same vertical plane being circumferentially staggered by 180*/n, wherein n is the number of bobbins in each layer. The double twist spindle of the present invention is useful for the twisting and assembling of all textile filaments and particularly the stranding of metallic fibers.

United States Patent 1191 Gre [ Apr. 30, 1974 [54] DOUBLE TWIST SPINDLEFOREIGN PATENTS OR APPLICATIONS [75] Inventor: Michel Jean Baf-lfi-Duc,1,318,879 1/l963 France 57/ss.s2 France 348,345 9/1960 Switzerland.57/58.52 [73] Assignee: Sodetal Societe Pour Le Development Du FilMetanique SA Przmary ExammerDonald E. Watkins Paris France Attorney,Agent, or FirmCushman, Darby & 22 Filed: May 3, 1973 Cushma [21] Appl.N0.2 356,799 57 ABSTRACT The present invention related to a double twistspindle Foreign Appllcallon Priority Dam for the twisting and assemblingof textile filaments.

May 4, 1972 France 72.16922 The spindle assembly comprises a stator, arotor, several layers of feed bobbins mounted on the stator, with [52]US. Cl. 57/58.52 each layer of bobbins regularly distributed around the[51] Int. Cl. DOlh 1/10, DOlh 7/86 spindle axis, with the verticalplanes defined by the [58] Field of Search 57/34 R, 3, 13, 58.49, axisof a plurality of bobbins of two successive layers 57/58.52, 58.54,58.55, 58.83 arranged in the same vertical plane being circumferentiallystaggered by 180/n, wherein n is the number of ['56] References Citedbobbins in each layer.

UNITED STATES PATENTS The double twist spindle of the present inventionis 2,546,977 4/1951 Clary etal. 57/58.55 useful the twisting andassembling Of all twile 2,353,104 7/1944 Winslow 57/58.52 filaments andparticularly the stranding of metallic 1,263,405 4/1918 Grondahl57/58.52 fibers. 2,464,860 3/1949 Green 57/58.52 3,119,224 l/l964 Kocks57/58:52 9 Chums, 3 Drawing Flgllres w 2 I 20+ 22 I /.9 I 25a:

DOUBLE TWIST SPINDLE BACKGROUND or THE INVENTION The present inventionrelates to a double twist spindle for the twisting and assembling offilaments into strands. Such double twist spindles, at times also calledstrand-making spindles, are particularly used for the manufacture ofcertain industrial fiber assemblies such as, for example, in themanufacture of pneumatic cables with a base oforganic textile fibers,metallic fibers or glass fibers.

A conventional double twist strand-making spindle generally comprises arotor having an axial conduit and at least radial conduit having an axislocated essentially perpendicular to the axis of the spindle, a statormounted above the rotor and mounted by appropriate means such as magnetsso that the stator does not inter: fere with rotor rotation, and meansfor mounting bobbins of filaments on the stator.

In operation, the filaments contained on the bobbins are unrolled fromthe bobbins and penetrate theaxial conduit of the spindle after passingover a converging guide located on the top of the spindle. After a firstreturn of about90, the filaments are passed through the rotor radialconduit, wherein the filaments undergo a first twisting. Upon exit fromthe radial conduit, the filaments undergo a second return of about 90and thereafter pass on an essentially unrestricted path, whileundergoing a second twisting, toward a strand guide, such as a pigtailguide, located axially above the spindle. The double twist strand soformed can be passed to any appropriate rewinding apparatus.

Because of spindle rotation, a balloon of filaments is formed around thespindle-bobbin assembly during the unrestrained travel ofthe filamentsbetween the radial conduit exit and the strand guide located above thespindle. A j

The number of feed bobbins mounted on the stator varies depending uponthe type of strand production, and a major problem of these conventionaldouble twist spindles is in the housing of the bobbins in the balloonfilament interior. In order to reduce the number of bobbin changes(which require-a machine stop) it is advantageous to locate bobbins ofas large as possible individual capacity in the filamentballoon.interior. Thus, in theory, it would be desirable to use a filamentballoon of as large a volume as is possible.

For a spindle of given size, the volume of the filament balloon isrelated to the speed of rotation, and theoretically, increases with thespindle speed of rotation.

However, the mechanical stress to which the spindle assembly issubjected, increases rapidly with the speed of rotation, and the sameeffect is noted for the tension upon the filaments in the balloon.Furthermore, the filaments in the balloon are subject in the ambientatmosphere to an aerodynamic braking in proportion to the volumethereof.

For the above reasons, it is generally necessary to fix a spindlerotation speed limit, so as to assure that the spindle is operated withthe required degree of confidence. This fixed spindle rotation speedlimit determines a given filament balloon volume in which the feedbobbins must be located.

Another problem of the prior double twist spindle is encountered whenthe spindle is started or stopped. During those periods of accelerationor deceleration, which must be of a duration such as to avoid undulyhigh tensions in the filaments and sudden jerks in the mechanicalassembly, the filament balloon is of a volume which is lower than itsnormal operating volume or regular volume. Therefore, it is important toinsure that the filaments do not catch upon the feed bobbins or the feedbobbin mounting means located on the stator.

On most of the double twist spindles used by the prior art, the bobbinsare disposed on the same level or plane around the axis of the spindle.In an alternative em-. bodiment described in French Pat. No. 762,556,the axis of the bobbins is parallel to the axis of the spindle aroundwhich the bobbins are regularly distributed. These devices givegenerally satisfactory industrial results for strands comprising up tothree filaments (or three ends). However, in the production offourfilament strands (or strands of four ends),-the filament bobbindimension must be considerably reduced in size in order to fit withinthe balloon, and thus the capacity of each filament bobbin is reduced,with the result that frequent stops of the machine are required forbobbin changes, and it will be readily appreciated that such frequentstops are highly undesirable for profitable industrial production.

US. Pat. No. 2,546,977 discloses a double twist spindle for a strandingmachine wherein the filament bobbins are arranged in a single layer,with the bobbin axes being non-perpendicular to the spindle axis.

Swiss Pat. No. 348,345 (which is generally similar to French Pat. No.762,556 discussed above) concerns a double twist spindle wherein thebobbins are regularly arranged around the spindle in one ortwo layers,with the axes of the bobbins being parallel to the spindle axis. US.Pat. No. 1,480,207 discloses a vertical twisting spindle for a strandingmachine wherein the bobbin axes are perpendicular to the spindle axis,with the bobbins arranged in two layers without any angular shifting ofbobbins. British Pat. No. 1,085,133 discloses a horizontal strandingmachine including a reel carrier having a stationary horizontal beamaround which filament bobbins are arranged in several layers or stages,the bobbin axes being perpendicular to the beam. The bobbins of twoconsecutive stages are shifted by about 90 (note FIGQ S).

SUMMARY OF THE INVENTION The present invention relates to asubstantially vertical double twist spindle for the twisting andassembling of the textile filaments. The spindle includesa rotor and astator, with filament bobbins mounted on the stator, with the filamentsbobbins regularly distributed around the stator in a plurality ofvertical planes and in a plurality of layers. Each bobbin layer containsn bobbins, wherein n is at least two, with the bobbins in the samevertical plane describing a set of substantially vertically alignedbobbins. The vertical planes of any two adjacent bobbin sets arecircumferentially staggered by l/n.

In a preferred embodiment, the double twist spindle includes a filamentballoon spacer mounted on or near the top of the spindle. The filamentballoon spacer,

' which can be a ring mounted around the spindle axis,

serves to prevent the filaments which form the balloon from catching onthe filament bobbins or filament bobbin mounting means during startingand stopping of the spindle.

DESCRIPTION OF THE INVENTION The present invention provides a doubletwist spindle which obviates the disadvantages of the prior art doubletwist spindles described above.

The present invention relates to a double twist spindle havingsubstantially vertical axis. The spindle includes a rotor, stator, andintegral mounting brackets on the stator for the mounting of feedbobbins. The arrangement of the bobbins on the stator is most importantto the successful operation of the double twist spindle. The bobbins areregularly distributed around the stator in several layers, at least onelayer containing n bobbins, wherein n is at least two. The individualbobbins of the different layers are mounted in vertical relationship.The axes of each bobbin forms a substantially vertical plane which iscircumferentially staggered aroundthe stator from the vertical plane ofthe bobbin of adjacent layer by 180/n. Preferably, the axis of each.

I prior art for the production of three-filament strands (or three-endstrands) are used, with two bobbin layers and two bobbins per layeraccording to the process of the present invention, four-filament strandsmay be readily produced. If, on-the' other hand, three bobbin layers areutilized, fiveor six-filament strands may be readily manufactured. Thenumber of bobbins may vary somewhat from one layer to another, but atleast one layer will contain n bobbins, wherein n is at least two. Also,n represents-the maximum number of bobbins in any of the layers.

The present invention also relates to a double twist spindle whichincludes means for spacing the filament balloon from the spindle. Thisfilament balloon spacer keeps the balloon open during the time ofstarting and stopping the spindle, when the prior art balloons generallyhave a significantly smaller volume than the normal operational volume.The filament balloon spacer maintains the filaments away from thebobbins and bobbin holders and thereby permits an increase of theavailable volume of the bobbins, by increasing the minimum volume of theballoon.

In one preferred embodiment, the spindle carries two layers of bobbinsand the: filament balloon spacer is formed by a ring mounted above thespindle axis. This ring is conveniently mounted on an extension of therotor. The ringmay be stationary or may be rotatable, and may turn in anfree manner. When the spindle is rotating at normal speeds, the diameterof the balloon at the height of the ring filament balloon spacer isgreater than the diameter of the ring, and there is no contact betweenthe ring and the filaments. However, during at least part of the periodsof starting and stopping the spindle, the filaments rub'on the ringfilament balloon spacer. The diameter of the ring is of a predeterminedsize in order to permit the filament balloon to maintain asufficientvolume so that the strand does not contact the bobbins or the bobbinholders during periods of starting and stopping the spindle. In oneparticularly advantageous form of this embodiment, the spindle carriestwo layers of bobbins and the filament bal-' DESCRIPTION OF THE DRAWINGThe present invention will be more readily understood with reference tothe accompanying drawings wherein:

FIG. 1 shows a side partial elevation view of a double twist spindlecarrying two bobbins layers, with two bobbins per layer;

FIG. 2 is an overheadelevational view of the double twist spindle ofFIG. 1; and

FIG. 3 is a partial sectional view of the double twist spindle of FIG.1.

The double twist spindle of the accompanying drawings includes a rotor1, having an essentially circular plate 2 and a spindle 3; Rotor l ismounted on fixed support 5 by way of ball bearings 4. Rotor l is rotatedby conventional means (not shown), for instance, by drive gears. Rotor 1is provided with axial conduit 6 in spindle 3, with axial conduit 6communicating with two radial conduits 7, 7 located in plate 2 at acircumferential difference from one another of 180. (In operation, onlyradial conduit 7 is used, with conduit7' provided only. for balancingrotor LObviously, other means of balancing rotor 1 may be used, ifdesired). Two circular recesses 8 are provided at the intersection ofaxial conduit 6 and radial conduits 7'for the housing of rotating guides9. An additional set of rotating guides. 10 are provided at theperiphery of plate 2 and tangential to the exit of radial conduits 7.

Rotor 1 supports, by means of bearings 11, 11a, a stator 12 whichincludes circular plate l3and hub 14. The stator 12 is restrained fromrotation by magnets 15, lS'a fixed on the underside of plate 13, nearits outer periphery and magnets 15, 15a on the upper side of fixedsupport 5. i

Stator 12 includes feed bobbin mounting means,such as spindles l6, 16'mounted on hub 14. Bobbins 25, 25 are rotatably mounted on spindles l6,16'. Preferably, spindles 16, 16' includes magnetic braking means (notshown) which are individually adjustable in order to maintain relativeconstant tension upon the filaments during the unwinding of the bobbins.The other bobbins.25a, 25a are mounted on similar spindles. The axes ofthe same layer of bobbins, 25, 25 and 25a, 25'a are located in the samevertical plane, with the axes of bobbins 25, 25 being located in avertical plane which is circumferentially staggered by (180l2) inrelation to the vertical plane of bobbins 25a, 25a. Each spindle (andassociated bobbin) is inclined by 12 in relation to the horizontal, andthe distance between the two layers of bobbins is mm. An axial tube 17is screwed to the top of hub 14. The upper end of axial tube 17 carriesa guide 26, and the lower end of axial tube 17 is located in a recess inthe top of spindle 3. The axial tube 17 serves toadmit and converge thefilaments into axial conduit 6. Crosspiece 18 is mounted on the upperend of stator 12 and support guides 19 which serve to guide thefilaments from the bobbins 25 to the axial tube 17. Crosspiece 18 alsosupports the lower end of shaft 20, located along the axis of thespindle, which serves as an axis of rotation for balloon separator 21.Balloon separator 21 comprises a rotatable metallic ring connected by aframework such as spokes to a central hub which is mounted on shaft 20by means of ball bearings 22.

The double twist spindle preferably includes a balloon screen 23 in theform of a cylindrical skirt mounted on fixed support 5. Pigtail guide 24is mounted above the double twist spindle on the spindle axis.

In operation, the four'filaments are passed from their respectivebobbins 25 over guides 19 and through the axial tube 17 to axial conduit6. After passing through axial conduit 6 the filaments are subjected toa 90 turn around guide 9 and then pass through radial conduit 7 whereinthe filaments receive a first twisting. After a second 90 turn aroundguide 10, the filaments are passed in a unrestrained path toward pigtailguide 24, forming a balloon around the spindle due to rotation ofrotor 1. During passage between guide 10 and pigtail guide 24, thefilaments receive a second twisting. The

strand thereby obtained from the double twist spindle may be collectedon any appropriate winding device.

When metallic filaments are treated on the double twist spindle of thepresent invention, it is preferred to impart an extra temporarytwisting, by way of 'a false twist spindle, of the strand before thestrand is wound on the windingdevice.

During starting and stopping of the spindle, that is, during thoseperiods of time when the filament balloon does not have itsmaximum'volume, the filaments are prevented from catching on bobbins 25by balloon separator 21. The path of the filaments during the period ofminimum filament balloon volume is shown by a dotted line in FIGS. 1 and3.

The double twist spindle of the present invention is particularlyadvantageous for the manufacture of fourply strands (that is, strandshaving four ends) from steel fibers having a diameter of 0.220 mm. intoS- configurations twisted strand having 105 turns/m. The spindles cancarry four bobbins of an individual capacity of 13 kg of filaments withthe usable spindle charge thus being 52 kg of filaments.

The double twist spindle ofthe present invention is capable of makingall of the conventional twisting operations, with the amount of twistingvarying, for instance, from about 30 to about 400 turns/m by appropriatechanges in the rotor driving gears or other driving mechanisms. Thedouble twist spindle is capable of stranding together, two, three, fouror more filaments, for instance, filaments having a diameter betweenabout 0.10 mm and 0.30 mm. The filaments which form strands on thedouble twist spindle of the present invention, may be of any material,including natural and synthetic textile filaments, metallic filamentsand glass filaments.

It will be readily appreciated by those skilled in the art that thedouble twist spindle of the present invention is not restricted to thespindle shown on the accompanying drawings. Within the bounds of thepresent invention, numerous variations of the spindle may be utilized,including the number of bobbin layers, the number of bobbins per layer,the method of mounting the bobbins on the rotor, the method of brakingthe bobbins, the method of drivingthe rotor, the method -of forming theballoon separator, and the like.

What is claimed is:

1. A double twist spindle for the twisting and assembling of textilefilaments, said spindle mounted with a substantially vertical axis, saidspindle comprising rotor means, stator means mounted above and onsubstantially the same axis as said rotor means and cooperating withsaid rotor means to permit rotor means rotation, bobbin feed meansmounted on said stator means for mounting a plurality of filament feedbobbins regularly distributed around the stator means in a plurality ofsubstantially vertical planes and a plurality of substantiallyhorizontal layers, at least one layer containing n bobbins, wherein n isat least two, each vertical plane being circumferentially staggered byabout /n from the adjacent vertical plane.

2. A spindle according to claim 1, wherein each layer of filament feedbobbins contains two bobbins.

3. A spindle according to claim 2, wherein the bobbins in a layer are inthe same substantially vertical plane.

4. A spindle according to claim 3, wherein the filament feed bobbins aremounted in two layers.

5. A spindle according to claim 1, wherein the axes of the bobbins areinclined to the horizontal.

6. A spindle according to claim 5, wherein the angle of inclination isfrom about 10 to about 18.

7. A spindle according to claim 1, including balloon spacer meansmounted at or near the upper end of the spindle to keep the textilefilaments from contacting the filament feed bobbins during starting andstopping of the spindle.

8. A spindle according to claim 7, wherein the balloon spacer meansincludes a ring mounted around the axis of the spindle.

9. A spindle according to claim 8 wherein said ring is rotatably mountedaround said axis.

1 a: k a:

1. A double twist spindle for the twisting and assembling of textilefilaments, said spindle mounted with a substantially vertical axis, saidspindle comprising rotor means, stator means mounted above and onsubstantially the same axis as said rotor means and cooperating withsaid rotor means to permit rotor means rotation, bobbin feed meansmounted on said stator means for mounting a plurality of filament feedbobbins regularly distributed around the stator means in a plurality ofsubstantially vertical planes and a plurality of substantiallyhorizontal layers, at least one layer containing n bobbins, wherein n isat least two, each vertical plane being circumferentially staggered byabout 180*/n from the adjacent vertical plane.
 2. A spindle according toclaim 1, wherein each layer of filament feed bobbins contains twobobbins.
 3. A spindle according to claim 2, wherein the bobbins in alayer are in the same substantially vertical plane.
 4. A spindleaccording to claim 3, wherein the filament feed bobbins are mounted intwo layers.
 5. A spindle according to claim 1, wherein the axes of thebobbins are inclined to the horizontal.
 6. A spindle according to claim5, wherein the angle of inclination is from about 10* to about 18*.
 7. Aspindle according to claim 1, including balloon spacer means mounted ator near the upper end of the spindle to keep the textile filaments fromcontacting the filament feed bobbins during starting and stopping of thespindle.
 8. A spindle according to claim 7, wherein the balloon spacermeans includes a ring mounted around the axis of the spindle.
 9. Aspindle according to claim 8 wherein said ring is rotatably mountedaround said axis.